Seam for sewing together fabric



I March 8, 1938. 4 HUBER 2,110,667

SEAM FOR SEWING TOGETHER FABRIC File d Jan. 7, 1955 2 Shees-Sheet 1 arch 8, 1938. G. HUBER 2,110,667

SEAM FOR SEWING TOGETHER FABRIC Filed Jan. 7, 1935 2 Sheets-Sheet 2 f r I Patented Mar. 8, 1938 Ni'iE STATES Application January In Germany 8 Claims.

7, 1935, Serial No. 731 January 6, 1934 (Granted under the provisions of sec. 14, act of March 2, 1927; 357 0. G.

The subject-matter of the invention is the production of a seam for connecting pieces of cloth so that the seam on one side of the sewed-together pieces is invisible.

For the production of such a seam, the pieces of cloth to be connected are, in the usual way, placed side-by-side with their upturned relatively positioned edges, whereupon the edges are sewed together and are overseamed.

Heretofore, such seams were produced in this way, that at first the edges were sewed together by means of a first seam and then the said seam was covered by an overseam, in which the pieces of cloth were stitched with a blind stitch. Moreover, heretofore such seams were made in such a way, that they were made by means of two needles, one of said needles stitching one of the pieces of cloth with a blind stitch and then passing through the edges, whereas the other needle first stitched the other piece or" cloth with a blind stitch in the opposite direction and then stitching through the edges, the needle threads being then looked at the entrance and exit stitches each by a looper-thread.

These heretofore used stitching methods of such a seam, however, have considerable disadvantages. Especially the last named manner of stitching has the disadvantage, that for the two needles two stitching devices are required, resulting in a complication of the machine, because of the driving mechanisms required for operating the needles, as well as in a difficult operation of such a machine, especially in case of disturbances, where, for instance, the thread breaks, aside from the fact, that because of the distance between the needles, sharp edges can not be sewed.

Contrary thereto, in accordance with the present invention such a seam is produced with the aid of only one straight or curved needle, which passes perpendicular or at an angle. relative to the feed of the cloth or oscillates relative thereto. For this purpose, the needle at each operation is guided in the same direction, so that alternately it stitches at one movement first the one piece of cloth the manner of a blind stitch and then the upright positioned edges of the two pieces of cloth, while during the next movement it first stitches the upright positioned edges of the pieces of cloth and then the second piece of cloth in the manner of a blind stitch, whereupon the timely guided needle thread is locked at the entering and exit places by the looper thread covering the upright positioned edges. A further feature of the invention consists in this, that for the production of a very fiat seam the originally upright positioned edges of the pieces of cloth prior to being sewed together, are separated and are partly turned down and thereupon are entirely turned down in the plane of the pieces of cloth by the seam made according to this invention.

On the drawings, the invention is diagrammatically shown by way of illustration in two embodiments. In the drawings, Fig. 1 is a perspective view of the seam production in diagrammatic illustration. Fig. 2 shows the 3- thread seam, shownv in Fig. l, on an enlarged scale (the same being produced by a needle-thread and two looper threads). Fig. 3 shows on an enlarged scale a correspondingly made 2-thread seam (made with one needle thread and one looper thread). Fig. 4 is a section along AB in Fig. 3; Fig. 5 is a section along C--D in Fig. 3; Fig. 6 is a perspective view of another embodiment of the invention shown diagrammatically. Fig. '7 shows on an enlarged scale the. 3-thread seam shown in Fig. 6 (produced by one needle thread and two looper threads). Fig. 8 shows on an enlarged scale a correspondingly produced Z-thread seam (made by one needle thread and one looper thread). Fig. 9 is a section along A-B in Fig. 7; Fig. 10 is a section along C-D in Fig. 7 Fig. 11 is a section along E-F in Fig. 8; Fig. 12 is a section along GI-I in Fig. 8.

According to the invention, the sewing together and overseaming of the placed-together edges of the pieces of cloth i and 2 to be connected, is performed in the following manner:

The pieces of cloth 5 and 2 are placed with their upright positioned edges 6 and l on the pressure plates 3 and i of the sewing machine table, which pressure plates, by means of springs 5, are preferably yieldingly mounted, as shown in Fig. 1. The upright relatively positioned edges t, l, of the pieces of cloth i, 2, are pressed down by the tongue ii, which is resiliently pressed against the front of the edges of the cloth, so that a very flat seam is produced. The pieces of cloth l, 2, moreover, are held and guided by the pressure feet 9, iii, the latter being so disposed, that they press the edges of the cloth under a certain resilient pressure against each other to be sewed. These thusly guided pieces of cloth are now sewed together without a preliminary seam by means of a straight or curved needle. ll, which is moved or oscillated nerpendicularly or anguiarly relative tothe feed of the pieces of cloth. For this purpose the needle thread it is guided by the needle H in such a way, that the needle H first passes through the one piece of cloth, e. g. the piece of cloth 2 at I3 in the manner of a blind stitch and then passes through the relatively upturned edges '6, 1, whereas, at the next movement, it passes through the upright positioned edges 6, l, and then through the other piece of cloth, the piece of cloth 5, at M, in the manner of a blind stitch. This sequence of stitches is alternately continued, the needle thread ['2 being every time locked by the looper thread l5 at the entering and exit places. These lockings between the needle thread and the looper thread, therefore, occur once at the entrance places of the blind stitches and, on the other hand, at the edges of the pieces of cloth.

It is obvious that the locking of the needle thread l2 can be effected with only one looper thread 55 or also with two looper threads, I5, 55

Such a .Z-thread seam with a looper thread is shown in Figs. 3, 4 and 5, whereas in Figs. 1 and 2 is shown a B-threaded seam with two looper threads.

The stitching of the pieces of cloth I and 2 in the manner of a blind stitch is made possible by arching members, which somewhat raise the cloth. In the embodiment shown, this purpose is served by the arching pins l6 and H, which are alternately operated from the sewing machine shaft by means of a lever transmission It.

The arching pins, instead of being thus alternately operated, can also be operated so that only either one or the other pin presents the cloth to the needle H for stitching, in which case the locking together of the needle thread and looper thread is done on that side, on which the arching pin is not operated, the locked thread then lying directly on the corresponding edge of the cloth, in which event the seam is flattened only toward one side, as shown by Figs. 4 and 5.

The locking of the needle thread and looper thread occurs in this way, that, for instance, the needle first passes through the edges of the pieces of cloth and then stitches the one piece of cloth, for instance at id, in the manner of a blind stitch. After this forward movement, the looper i@, which swings from the left upwards toward the right as the needle ll goes back, enters through the needle thread loop 29, presented to it by the needle ll and brings its looper thread i5 to the looper 2!, which carries the looper thread E5 Ihis looper swings from above toward the right below and brings its looper thread loop 22 to the needle H during the next forward movement of the same, so that in this manner the locking of the needle thread 2 is effected. In the production of a Z-thread seam with only one looper thread, the looper 2! does not carry a covering thread, but engages the covering thread carried by the looper l9 and brings the same to the other side of the needle I l It is obvious that the lockings can occur in any desired sequence and in any desired selection of the ratio of the number of stitches.

The invention enables the production of a scam in which the pieces of cloth are sewed together with their upright positioned edges and are overseamed and this by means of only one needle, so that a very durable and flat seam is produced.

A further embodiment of the invention is shown in Figs. 6 to 12, in which case the advantage is obtained, that the seam still becomes flatter, which is effected in this way, that the orig naily upright relatively positioned edges, prior to being sewed together, are separated from each other or partly turned down and then are sewed together and overseamed by only one needle, so that the edges of the material are turned down substantially into parallelism with and in slightly spaced relation to the main body of the material.

In this case, the sewing together and overseaming of the placed-together edges of the pieces of cloth 25 and 2? to be connected, occurs as follows:

he pieces of cloth 2t and 2'! are placed together with their upright relatively positioned edges 39 and (ii on the pressure plates 28 and 29 on the sewing machine table, which pressure plates are also yieldingly mounted, like the pressure plates 3 and 4 in Fig. 1. The upright relatively positioned edges 30 and 3|, prior to the stitching by the needle 32, are separated from each other by a correspondingly shaped tongue 33 and are partly laterally turned down. When the edges of the pieces of cloth occupy this position shown in Fig. 6, the needle pierces the same in such a way, that it first pierces the one piece of cloth, for instance the piece 21 at 34 in the manner of a blind stitch, and thereupon pierces the edges of the two pieces of cloth and thereupon the other piece of cloth at 35, also in the manner of a blind stitch. At the next movement of the needle, the needle 32 pierces merely the edges of the cloth at 36, 3?, without piercing the pieces of cloth. The needle thread 38, carried by the needle 32, being thus alternately guided thereby, is then locked with the looper thread 39, the lockings between the needle thread 38 and the looper thread 39 corresponding to the thus described movements of the needle 32, occurring only at the entrance places of the blind stitches in the one sequence of stitches, whereas during the other sequence of stitches the lockings occur only at the edges of the pieces of cloth, that is at 35, 31.

The edges of the cloth which prior to the piercing of the needle 32 have been partly turned down by the tongue 53, are further turned down after the next sequence of stitches by the overseam thread 39 locked at the places of the blind stitches, so that the originally upright positioned edges are turned down substantially into parallelism with and in slightly spaced relation to the main body of the material, resulting in a very fiat seam. Preferably, the pieces of cloth 26, 2?, are guided by the pressure plates 42 acting in the manner of a pressure foot.

It is evident that the needle thread guided in the above mentioned sequence of stitches can be locked with one overseam thread as well as with two overseam threads, the nature of the seam not i being changed thereby. Such a Z-thread seam is shown in Figs. 8, 1]. and 12, whereas Figs. 6, '7, 9 and 10 show the 3-thread seam. The 3-thread seam diiiers from the 2-thread seam merely in this, that the 2 looper threads 35', 39", are interlooped in the center of the fiat seam at M In the sequence of stitches, in which the pieces of cloth are pierced in the manner of a blind stitch, the piece of cloth is presented to the needle to be pierced thereby by any desired arching members. In accordance with the embodiment in Fig. 6, two arching pins 4! are used for this purpose, which are simultaneously operated.

It is obvious, that the order of stitches of the stitch sequence I (blind stitch, piercing, blind stitch as shown by Figs. 9 and ll) and of the stitch. sequence II (piercing such as shown by Figs. 10 and 12) can be varied as desired, that is to say, that for instance, in place of the continual alternation the stitch sequence I or the stitch sequence II can be carried out several times in succession.

By the formation of the seam in the above described manner, aside from the production of an extremely fiat seam, the further advantage is obtained that the lockings 36, 31, located at the edges, come to lie under the turned-down edges 3i), 3 I.

Obviously, the seam according to this invention can be made instead of with only one needle, also with two needles working in succession and either one or two overseam threads.

I claim:

1. A seam connecting and o-verseaming pieces of cloth having their edge portions upturned and abutting, said seam comprising a single needle thread passing back and forth through the upturned edge portions of the pieces of cloth and also through each piece of cloth in the form of blind stitches at points spaced from the said upturned edges, and looper thread means passing back and forth over the said upturned edges and having loops some of which cooperate with said single needle thread at said blind stitch points and others of which cooperate with said single needle thread directly adjacent to each of said upturned edges, whereby the upturned edges are bound together against separation and an overseam is provided overlying said upturned edges.

2. A seam connecting and oversearning pieces of cloth having their edge portions upturned and abutting, said seam comprising a single needle thread passing back and forth through the upturned edge portions of the'pieces of cloth and also through each piece of cloth in the form of blind stitches at points spaced from the said upturned edges, and a plurality of looper threads extending over the said upturned edges and having loops some of which cooperate with said single needle thread at said blind stitch points and others of which cooperate with said single needle thread directly adjacent to each of said up turned edges, whereby the upturned edges are bound together against separation and an overseam is provided overlying said upturned edges.

3. A seam connecting and overseaming pieces of cloth having their edge portions upturned and abutting, said seam comprising a single needle thread passing back and forth through the upturned edge portions of the pieces of cloth and also through each piece of cloth in the form of blind stitches at points spaced from the said upturned edges, and a single looper thread passing back and forth over the said upturned edges and having loops some of which cooperate with said single needle thread at said blind stitch points and others of which cooperate with said single needle thread directly adjacent to each of said upturned edges, whereby the upturned edges are bound together against separation and an overseam is provided overlying said upturned edges.

4. A seam connecting and overseaming pieces of cloth having their edge portions upturned and abutting, said seam comprising a single needle thread passing at the beginning of one stitch from one side of the said upturned edges through said upturned edges and then through one of the pieces of cloth in the form of a blind stitch at a point spaced from said upturned edges, then reversely from said blind stitch back through the said upturned edges, then, at the next stitch,

passing first through the other piece of cloth in the form of a blind stitch at a point spaced from the said upturned edges, then through the said upturned edges, then reversely through said upturned edges back to said second mentioned blind stitch and so on throughout succeeding stitches, and looper thread means overlying said upturned edges and having loops cooperating with said single needle thread at said blind stitch points, at the point of beginning each alternate stitch directly adjacent to the upturned edge of one of the pieces of cloth, and at the point of reversal of the needle thread at each of the other alternate stitches directly adjacent to the upturned edge of the other of the pieces of cloth, whereby the said upturned edges are bound together against separation and an overseam is provided overlying the said upturned edges.

5. A seam as set forth in claim 3 in which the looper thread means comprises a single looper thread.

6. A seam as set forth in claim 3 in which the looper thread means comprises a plurality of looper threads.

7. A seam connecting and overseaming pieces of cloth having their edge portions upturned and abutting, said seam comprising a single needle thread passing at each alternate stitch back and forth through the said upturned edges and also through each piece of cloth in the form of a blind stitch at points spaced from said upturned edges, said single needle thread at each intermediate stitch passing back and forth through only the said upturned edges, and looper thread means overlying said upturned edges and having loops cooperating with said single needle thread at said blind stitch points and also with each intermediate stitch of said single needle thread directly adjacent to each of said upturned edges, whereby the upturned edges are bound together against separation and an overseam. is provided overlying said upturned edges.

8. A seam as set forth in claim 7 in which the looper thread means comprises a plurality of looper threads.

GUSTAV HUBER. 

